Contact: Britt Storck, PLA, Principal, Alta
The Atlanta BeltLine stands as one of the Southeast US’s signature trails, offering a distinctive loop around the city of Atlanta that fosters connections between people, neighborhoods, and destinations. Alta has led the way in guiding a team of consultants through the design and construction for Segment 4 of the BeltLine’s Westside Trail championing a climate-positive design approach that delivers economic benefits for community and the planet.
As development progresses along the BeltLine, Alta remains dedicated to the project’s vision of sustainable public space. In our role as environmental stewards, landscape architects are responsible for championing climate-positive outcomes that not only include but surpass carbon neutrality. For Westside Trail Segment 4, Alta worked closely with ABI and Astra Group, LLC, to prioritize these benefits by integrating resilient materials and construction methods into the design program.
One of the largest influences of carbon-positive design for trail corridors is the overall impact to existing trees. Tree removal from a site produces a lot of emissions: mobilizing equipment to the site, machinery to fall the trees, grind the limbs and stumps, and trucking the lumber off-site. In addition to the emissions, tree removal diminishes existing carbon storage capacity. Removing trees disturbs the soil and releases carbon that has been sequestered in the soil into our atmosphere. Through detailed analyses, the design team determined that preserving as many trees as possible and making a strong effort to protect the largest trees on the site greatly affected the net carbon emissions of the project. Alta landscape architects, consulting arborist Arborguard, and climate positive experts Pamela Conrad and her Climate Positive Design team tracked the health and impact of 2,871 trees surveyed, with 1,885 preserved. Of the trees requiring removal for the project, 1,671 were dead, dying, or hazardous trees. Altogether, the team was able to protect two-thirds of the project’s tree cover. For one 30-inch diameter tree, the design team calculated that saving it had a net positive impact, even if a small retaining wall had to be built to save it.
When tree removal was necessary, Alta’s landscape architects determined tree spacing guidelines that maximized the number of trees planted, without compromising future tree growth and health. Over 1,500 trees were proposed across the project; more additional inches of trees were proposed to be planted than to be removed.
In addition to providing a meticulous set of tree protection and tree planting plans, Alta landscape architects developed a robust, diverse planting design for Westside Segment 4. The design team strived for a 100% native palette with 168 types of native species of shrub and herbaceous perennials across 12 acres. The palette included many types of perennial grasses, which tend to be better performers for carbon sequestration than other plants. Once established, this landscape will provide carbon storage and wildlife habitat.
These detailed elements of landscape design represent just a few ways that Alta and their partners were able to work toward a climate positive result with one trail segment. ABI’s value of resilient design and quality landscape plans provided the opportunity for the design team to apply new research and solutions for reducing and sequestering carbon emissions in future projects.
